1. Technical Field
The present disclosure relates to a photographing optical lens assembly, an image capturing unit and a mobile device, more particularly to a photographing optical lens assembly and an image capturing unit applicable to a mobile device.
2. Description of Related Art
In recent years, with the popularity of mobile terminals having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.
A conventional optical system employed in a portable electronic product mainly adopts a five-element lens structure. Due to the popularity of mobile terminals with high-end specifications, such as smart phones, tablet personal computers and wearable apparatus, the requirements for high resolution and image quality of present compact optical systems increase significantly. However, the conventional optical systems cannot satisfy these requirements of the compact optical systems.
Other conventional compact optical systems with six-element lens structure enhance image quality and resolution. However, in order to keep a compact optical system, the air gap in a paraxial region between the first lens element and the second lens element is extremely small. It is thereby unfavorable for assembling. Also, since the air gap between the first lens element and the second lens element is extremely small, the first lens element is easy to be in contact with the second lens element which leads to worse image quality.